Coating for flame-retarding coverings and method of manufacturing the same



Patented June 17, 1930 UNITED STATES PATENT OFFICE HARRY N. BOCKUS, OF MAPLEWOOD, NEW JERSEY, ASSIGNOR T SOLAR COMPOUNDS CORPORATION, OF LINDEN, NEW JERSEY, ACOBPQRATION OF NEW JERSEY COATING FOR FLAME-BETARDING COVERINGS AND METHOD OF MANUFACTURING THE SAME No Drawing.

to one skilled in' the art.

ject 0 It is now commercial practice to make the coverings for wires and cables flame-resistant by treating them with a hydro-carbon such as vegetable oils or fatty acid pitches. Such a covering in accordance with best practice is subsequently coated with paraffin in order to give it a glossy finish of good appearance, to prevent sticking when coiled and to afford some degree of lubricating quality to facilitate fishing. Such a practice as described has certain distinct disadvantages and certain distinct limitations which prevent the widest range of usefulness of flame-retarding covered wires and cables. For instance, it has never been possible to color such coatings distinctly as is necessary to indicate the polarity'of wires. The paraffin coating cannot be used successfully with coloring matter, either in the form of a dye or a pigment because paraflin has not suflicient covering pOWer to carry a pigment, and a dye in paraffin Will show itself or bleed out. Unless flame-retarding coverings for wires can be colored satisfactorily for polarity it is evident that they will not lend themselves to widest usefulness. Not only is it impracticable to color any coating having paraflin thereover but in general, heretofore no colored coating has been known which would remain fast when applied over a flame-resistant covering because the solventin any such coating always affected the free oils and thereby brought about discoloration of the pigment. One of the-principal objects of the present invention, therefore, is to provide an improved compound which can be used as a colored covering for a flame-retarding coating having a hydro-carbon base.

Another disadvantage of known coverings having a paraffin coating is thatthe paraflin will melt off under heat. Under other conditions paraffin may crack and fiake off upon fiexin of the cable or wire. A further ob- %the present invention is to overcome Application filed August 8, 1928. Serial No. 298,409.

these objections to parafiin while'retaining all of the advantages thereof and provide a covering compound which shall have a glossy finish of good appearance, but nonsticking when the cable or wire is coiled and whose finish shall be such as to facilitate fishing. These physical properties with the ability to carry satisfactorily a coloring pigment which will be fast involves a new compound in which the various factors for the purpose intended have all been reckoned with and successfully met.

The improved compound consists essentially of four different ingredients each contributing to the desired physical properties and each affording some degree of latitude in selection as to species. For instance, as a base it is proposed to employ what is generally known in the trade as an alcohol soluble gum. One such gum now on the market is sold under the name of alcohol soluble manila gum. Such a gum may be available as a fossil gum or treated fossil gum or what is known as a synthetic gum or even an animal or vegetable gum. Such an alcohol soluble gum is dissolved in alcohol or its derivatives, combined with, if desired, coal tar derivatives such as benzol, toluol and Xylol constituting satisfactory solvents for the purpose. In the new compound is also included a plasticizer which may be either a vegetable oil or a glyco compound. A coloring pigment is also included preferably in the manner set forth in the method of manufacturing the compound to be described later. Of the ingredients recited it has been found, for example, that about six pounds (6 lbs.) of the alcohol soluble manila gum may be dissolved in about one gallon of denatured alcohol to which is added a plasticizer of castor oil inthe proportion of three per cent (3%) by weight of the above solution, and about twelve pounds (12 lbs.) of pigment. The compound described when apphed to a flame-resistant hydrocarbon covering on wires or cables presents an attractive glossy finish, prevents sticking when the wire is coiled, is substantially inipervious to grease and oil, facilitates fishing of the wire by reason of the surface finish and covers the base with a pigment of any desired color which is fast and effective for the purpose.

As is known coal-tar derivatives such as bcnzol, toluol and xylol are solvents for hydrocarbon coatings of the class referred to and accordingly in the compound described such a solvent will attack the hydrocarbon. In the present instance this is not objectionable but on the contrary is desired. within practical limits since the finely comminuted pigment is carried in suspension and to the extent that the said coal-tar derivatives attack the surface of the hydrocarbon to that extent will the hydrocarbon be impregnated with the pigment. When the volatile mattcr passes oil' the result will be that the pig simultaneously while grinding is carried on of the entire mass within a mill to comminute the pigment andbring about a homogeneous admixture. In following this method the agitation employed to bring the gum into solution may be carried on in the same mill to which the pigment and plasticizer are subsequently introduced for grinding, thereby making the'operation one of continuous stages and without additional handling of any of the materials.

The terms flame-proof, flame-retarding, flame-resistant, 'flame-repellant, fire-repellent, are used synonymously in .this art by those engaged in the industry to denot-ethat condition ofa covering for electrical conduits which satisfies the fire underwriters tests and it is in this sense that such of those words as are used herein, are

to be construed.

It will be understood from the description given that the properties of the improved compound are such as make it particularly useful as a covering for a flame-retarding coating on wires and cables but it is possible that other situations may present themselves where the compound may be employed to equal advantage and for the purpose of gbtaining the same general conditions sought What I claim is: y

1. As an article of manufacture, a conduit or coverin for wires consisting of a non-metallic jac et treated with a flame ref tarding hydro-carbon material including fatty acid pitches and a flexible colored.

or covering for wires consisting of a nonmetallic jacket treated with a flame retarding hydro-carbon material including fatty acid pitches and a colored coating comprising a solution of an alcohol soluble gum containing a pigment and a plasticizer.

3. As an article of manufacture, a conduit or coverin for wires consisting of a non-metallic jac et treated with a flame retarding hydro-carbon material including fatty acid pitches and a colored coating comprising a solution of an alcohol soluble gum containing a pigment and a coal tar derivative.

4. The method of treating the coverings of electrical conductors insulated with a flame retarding hydro-carbon including fatty acid pitches, for the purpose of indicating polarity of the conductor, which comprises applying to the covering a composition consisting of a solution of an alcohol soluble gum containing a pigment.

5. The method of treating electrical 'conductors insulated with a flame retardi h dro-carbon covering including fatty aci pitches, for the purpose of providing the same with a hard impervious glossy surface and also a colored coatin to indicate polarity, which comprises app ying to the covering an unheated composition consisting of a solution of an alcohol soluble gum containing a colored pigment and a plasticizer.

6. The method of treating electrical con- (luctors insulated with a flame-retarding hydro-carbon covering including fatty acid pitches, for the purpose of indicating polarity of the conductor, which comprises applying to the covering a colored coating consisting of a solution formed from about six (6) pounds of an alcohol soluble gum dissolved in about one gallon of thinner, a plasticizer to ,the extent of three percent (3%) by weight of the said solution and a colored pigment.

7. As an article of manufacture, a conduit or coverin for wires consisting of a non-metallic jac et treated with a flame-retarding hydro-carbon material including fatty acid pitches and a colored coating thereon comprising a solution of an alcoho soluble m containing a pigment and in which ti e pigment is present in greater wei ht than the T liis specification signed this 27th day of July, A. D. 1928.

HARRY N. BOCKUS. 

